Inflammatory cytokines in tears of patients with lacrimal duct obstruction

Sir,

We read with great interest the article by Wang et al1 published in the Indian Journal of Medical Research (IJMR). We have some observations and suggestions to make, which we believe will benefit the readers to get more insight from this article. First, the authors have included all unilateral cases, but it would have been interesting to know whether these were all primary acquired lacrimal duct obstruction cases or whether secondary acquired lacrimal duct obstruction cases were also included2. Second, the authors have mentioned that all 30 study participants received lacrimal catheterization and/or transnasal dacryocystorhinostomy according to their specific condition. However, it would have added value to know if those with acute dacryocystitis were treated with oral anti-inflammatory drugs and antibiotics before being subjected to surgery3.

Another question is that lacrimal syringing was excluded in acute dacryocystitis cases, and the contralateral eye was taken as control. It is unclear whether the authors performed syringing in the contralateral eye in these cases in the same sitting or not. Ideally, acute dacryocystitis cases should have been excluded for the individual and examiner’s comfort as sometimes it may not be feasible to obtain a convenient sample in these cases4. It would have also added value to know whether any of the participants had lacrimal pathology for more than six months as tear cytokine analysis done after six months of pathogenesis may not yield correct inflammatory cytokine levels and could contribute towards a potential bias.

The exclusion criteria also do not inform regarding the history of active sinusitis, punctal stenosis, punctal atresia and membranous punctum5. It would have been interesting to know if the authors encountered any of these in their study pool. The authors have also mentioned that tear samples were collected from both eyes. A necessary precaution to be taken while collecting the sample is that it should not touch the conjunctiva, otherwise there are the chances of cross-contamination and misdiagnosis6. The confidence level cut-off of the assay is also not mentioned.